This invention relates in general to methods of removing scale, and in particular to chemical methods of dissolving scale to remove it from the interior surfaces of processing equipment.
In many industrial processes, the buildup of scale on the interior surfaces of processing equipment is a significant problem. Materials such as alkaline metal salts precipitate out of the fluids being processed and form adherent deposits or scale on the surfaces of the equipment. For example, scale can form on the surfaces of evaporators, fermentors, and other equipment used in the manufacture of ethanol from corn. The buildup of scale can cause problems with heat transfer, fluid flow, and sanitation of the processing equipment.
Many different methods have been used for scale removal, including both physical and chemical removal methods. In the ethanol manufacturing industry, various mineral acids have been employed to dissolve the scale, sometimes in combination with caustic soda. To date, no universal and total solution to the scale problem has been uncovered. There is still a need for an effective and economical method of removing scale.